A vehicle disk brake has a brake anchor plate, which is to be fastened to the chassis of a vehicle, and a caliper or frame, which is held by the brake anchor plate and in which are accommodated friction linings that are pressed against a rotating brake disk.
Brakes of this type are generally known. The friction linings, consisting of supporting plate and friction layer, are conventionally guided axially in relation to the brake disk by means of bolts fastened to the brake anchor plate. “Axially” in the case of disk brakes generally means: in a direction parallel to the axis of rotation of the brake disk. “Radially” accordingly means a direction at right angles to an axial direction in the above sense. The brake anchor plate is in turn fastened to the wheel bearing.
The prior art of such vehicle brakes in the form of disk brakes is represented for example by the following documents: DE 1 238 284, DE 1 505 491, and corresponding U.S. Pat. No. 3,298,468 A, both of which are incorporated by reference herein in entirety, DE 1 575 920, DE 2 804 808, and corresponding U.S. Pat. No. 4,219,106 A, both of which are incorporated by reference herein in entirety, DE 2 845 404, DE 41 15 064 and DE 4 416 815, DE 101 13 347 A1, DE 41 15 064 A1 and DE 2211013 A, EP 0 729 871 A1, and corresponding U.S. Pat. No. 5,769,189 A, both of which are incorporated by reference herein in entirety.
In such vehicle disk brakes the friction lining is pressed by means of a brake piston by hydraulic pressure against a brake disk in order to brake the rotation thereof. For this purpose, hydraulic pressure is introduced under pressure into a hydraulic chamber, one boundary wall of which is formed by the brake piston. The pressure in the hydraulic chamber then leads to the displacement of the brake piston and hence of the friction lining in the direction of the brake disk.
In order that such a vehicle disk brake may be used not only as a service brake but also as an immobilizing brake—also known as parking brake, it is equipped with an additional actuator, which in the stationary state of the vehicle brings and keeps the friction linings in engagement with the brake disk. In this case, increasing use is being made of electric parking brakes that may be operated with so-called smart actuators. Here, as a rule by a smart actuator is meant an assembly that comprises an electric motor, optionally with a gear that reduces the rotational speed (and hence increases the torque) as well as an associated electronic control and power device. This assembly is mostly supplied by means of a LIN-, CAN-, or MOST bus, or in some other way with (immobilize, release, hold, etc.) control signals. However, because of the additional electronic components, the size of this assembly may be larger than that of a conventional actuator having an electric motor, the driving circuits of which are disposed spatially remote from it.
The vehicle disk brake for optimum space utilization is to be fitted as precisely as possible into the internal wheel contour. The available space is limited in this case by the additional parking brake unit. An added factor is that the parking brake unit built onto the brake caliper restricts access to the guide bolts for the brake linings and/or for the fastening bolts of the vehicle disk brake on the chassis. This makes assembly/disassembly more difficult. These circumstances arise in a particularly pronounced manner in compact vehicles with their smaller wheel diameters (for example 14 inches-17 inches). For this reason, in this category of vehicle it has previously hardly been possible to fit the electric parking brake and provide the gain in comfort associated therewith, for example during a hill start.